Merge #15419: qa: Always refresh cache to be out of ibd

fa2cdc9ac2 test: Simplify create_cache (MarcoFalke)
fa25210d62 qa: Fix wallet_txn_doublespend issue (MarcoFalke)
1111aecbb5 qa: Always refresh stale cache to be out of ibd (MarcoFalke)
fab0d85802 qa: Remove mocktime unless required (MarcoFalke)

Pull request description:

  When starting a test, we are always in IBD because the timestamps on cached blocks are in the past. Usually, we solve that by generating a block at the beginning of the test.

  That is clumsy and might even lead to other problems such as #15360 and https://github.com/bitcoin/bitcoin/issues/14446#issuecomment-461926598

  So fix that by getting rid of mocktime and always refreshing the last block of the cache when starting the test framework.

  Should fix #14446

Tree-SHA512: 6af09800f9c86131349a103af617a54551f5f3f3260d38e14e3f30fdd3d91a0feb0100c56cbb12eae4aeac5571ae4b530b16345cbb831d2670237b53351a22c1

1 files changed, 8 insertions, 0 deletions

diff --git a/test/functional/wallet_txn_doublespend.py b/test/functional/wallet_txn_doublespend.py
index f114d5ab68..9050e21247 100755
--- a/test/functional/wallet_txn_doublespend.py
+++ b/test/functional/wallet_txn_doublespend.py
@@ -34,6 +34,14 @@ class TxnMallTest(BitcoinTestFramework):
     def run_test(self):
         # All nodes should start with 1,250 BTC:
         starting_balance = 1250
+
+        # All nodes should be out of IBD.
+        # If the nodes are not all out of IBD, that can interfere with
+        # blockchain sync later in the test when nodes are connected, due to
+        # timing issues.
+        for n in self.nodes:
+            assert n.getblockchaininfo()["initialblockdownload"] == False
+
         for i in range(4):
             assert_equal(self.nodes[i].getbalance(), starting_balance)
             self.nodes[i].getnewaddress("")  # bug workaround, coins generated assigned to first getnewaddress!